Temperature-controller



A. N. OTIS.

TEMPERATURE CONTROLLER.

APPLICATION FILED JULY 18,1918.

Patented Sept. 21 192% 2 SHEETS-SHEET Iv Inventor. filber't lTOtis, by Hisyqttor'neg.

A, N. OTIS.

TEMPERATURE CONTROLLER.

APPLICATION FILED JULY 18. 1918.

2 SHEETSSHEET 2.

Patented Sept. 21, 1920.

Fig.5.

Inventor. Jqlbert TTOtis. b9 M62 H i sfittor-neg STATES PATENT @FFlGE.

ALBERT Ill. @338, 0? SCHENECTADY, NEW YORK, AS$IGNOR T0 GENERAL COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC V TEMPERATUEE-CONTRQ'JLEB.

Specification of Letters Patent.

Patented 21., T92@.

Application nlctl Zluly 18, 1918. Serial No.

To all whom it may G072-86i'/L.'

Be it known that T, ilnsnsr N. Orrs, a citizen of the United States, residing at Schenectady, in the county of Schenectady, of hew Yora, have invented certain new and useful Improvements in Temperatnre- Controllers, of which the following is a specification.

l /ly invention relates to improvements in the control of electric heating apparatus, and has reterenceinore specifically to apparatus for melting pots of the kind used on typese'ting machines and the like.

The nelting pot of a typesetting machine is supported on a movable frame which i subject to quick or abrupt movement. A.

iina ily coi'istnicted the arrangement or ermostat for controlling the electric sting units or" a melting pot s en such it was affected by this pot movement 0 as to cause chattering at the contacts. no of the objects of my invention is to proan improved arrangement whereby the veznent of the pot will not detriment-ally t the contacts. Another object of my vention is to so arrange the thermostat it will not be subject to the strains which have heretofore been placed upon the thermostat by reason of the contraction of the metal in cooling. @ther objects and purposes of my invention will in the course of the following specification in which have shown my invention embodied in crete form for purposes of illustration.

the accompanying drawings illustratg my invention, Figure 1 is a side elevation of a melting pot embodying my invention with a portion broken away; .2 is a front elevation of the same; Fig. 3 shows a detail. the mounting of the thermostatic device; Fig. is a sectional view oi the thermostat; ig. 5 is a sectional view taken right angles to Fig. T; Fig. 6 is a diagram showin the circuit connections.

referring to the drawings, 1 re the melting pot of a typesetting c ine which is heated by an electric unit A (Fig. 6). This melting pot is of standard construction and, inasmuch as it forms no part of my invention, need not be d scribed in detail. cient, t efor-e,

ally mounted i presents mounted on the top of this pot is shown in detail in Figs. 1 and 5. This thermostatic device comprises a casing 3 which incloses the switch mechanism and a frame 4 secured to the bottom of this casing for sup porting a thermostatic element 5. This thermostatic element and supporting frame are adapted to enter the metal of the pot, while the switch portion extends above, as shown in Figs. 1 and 2. The thermostatic element projects upward into the switch casin and terminates in a reduced po ion 6 which engages the switch mechanism to. cause the movement 0:5 the latter. The switch mechanism proper consists of a frame 7 pivoted on ball bearing pivots 8 so as to give practically a frictionless movement in response to the expansion of the thermostatic element. The expansion of the thermostatic element causes a movement of this frame on its pivot by engaging an eccentric 9 mounted on a shaft 10 carried by the frame. The engagement between the thermostatic elernent and the switch element is made in the form of an eccentric for the purpose of furnishing temperature adjustment. The eccentric is turned on its axis to give the adjustment by means of a worm 11 engaging the worm wheel 12 mounted upon the shaft 10.

Secured to the movable frame 7 is a switch arm 13 which projects upward between two fixed contacts 14- and 15. The switch arm 13 has two contacts, one of which 16 cooperates with tired contact 14 and the other 1'? with fixed contact 15. Exterior terminals 18 and 19 are provided for the fixed contacts 14 and 15 respectively. This switch arm is caused to normally occupy the position against the contact 14 hown in the o sents the leverage which the thermostatic 1 'J member acts upon the switch member and is made very small because the expansion of the $21312. ostatic e is sliglit. The switch member 13, however is located sonic (and the switch member itself is relatively 1. .L :.i connected to the sea long so as to give a relatively large movement at the contacts as compared to the actual expansion of the thermostatic element.

It will be observed that with this arrangement the movement of the contacts'is in a plane at right angles to the plane of movement of the melting pot, so that any abrupt movement of the melting pot will not cause movement of the contacts onthe switch arm yvith reference to the stationary contacts."The contacts 16 and 17 are spring mounted by means of the spring strips 21 and 22 so as to make a good contact, and were it not for the fact that movement of the contact is at right angles to the movement of the pot, the abrupt movement of the pot would afl'ect the contacts. As arranged, however, this difiiculty does not occur.

One of the important features of my invention is in the mounting of the thermostatic mechanism upon the melting pot. As heretofore arranged, this mounting of the thermostat upon the pot has :been made rigid. This has at times caused trouble by reason of the contraction strains put upon the thermostatic element by the soliditying of the metal to the ot. In order to overcome this difiiculty, have made the connection between the thermostatic mechanism and the pot resilient. In the arrangement shown in the drawings I have provided two bow springs 23 and 24:.secured to the bottom of the casing. These springs bear upon the top of the pot, and. screws 25 and 26, which loosely pass through; the bottom of the switch casing, are screwed in the top of the pot so as to keep the bow s rin s slightly under strain. It will also e 0% served that springs 23 and 24: are mounted for movement in'the plane of movement of the melting pot. The result is that the thermostatic mechanism, including the thermostatic element, may yield slightly as a whole, and strains on the mechanism are thereby overcome in 6 1 have shown a diagram of the circuit connections which ll employ, Re i'erri heating unit, circuit of which is controlled by the switch member 13 through the thermostatic memhe a instead of contr lnw circuit of the h recti y, the control is brought scene by lay consisting of two solenoids 2?! cne of which is connected to the thermostatic coif act it, while .2, V, 1, arrangement .L

cned

'29 and the conductor 32 to the negative side s drawing, it represents the tively. In Fig. 6 the parts are shown in a position in which the heating unit is energized from the positive side of the line through the switch member 31, the contact of the 'line. i This connection has been brought about by the energization of the solenoid 27 through the engagement of the thermostatic switch member 13 with sta- 'tionary contact 14. As soon as the solenoid 27 started to moveswitch member 31 to contact 29, the circuit of solenoid 27 was opened at contact30. Assuming that the tempera- ..ture of the melting pot has reached a point of the ins, switch member 31, contact 29, solenoid 28 and thermostatic contact 15 to the negative side of the. line. This will cause the switch member 31 to be moved over to engagement with the contact 30, thereby opening the heater circuit, and at the same time artially closing the circuit of solenoid- 27. he result is that the. circuit is never broken at the thermostatic contacts, but at the contacts 29 and 30-, and the switch member 31 'will have sufiicient movement and give a quick break such as is required. The thermostatic contacts merely complete the circuit for operating solenoids. I

It will be seen that I have devised a thermostatic switch 'airrangement which is rugged and well adapted for use on melting pots used for melting linotype metal and the like, since the movement of the melting pot and the solidifying of the metal will not have any detrimental efiect upon the ther-' mostat. 4

While I have described my invention as embodied in concrete form and as'operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that Eric not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is et forth in the annexed claims.

W hat I claim as new and desir by Letters o s United s- 1. The comh' man i n m mg the ing a thermostatic element projecting into the pot and an external switch element operated by the thermostatic element.

3. The combination with an electrically heated melting pot mounted for movement in a definite plane and a thermostatic device for controlling the temperature of the pot resiliently mounted for movement in the plane of movement of the pot, and having a thermostatic element projecting into the pot and an external switch element operated by the thermostatic element.

4. The combination with an electrically heated pivoted melting pot, of a thermostatic device resiliently mounted thereon comprising a pivoted frame, an elongated switch member secured to the frame, an eccentric adjustably mounted in said frame and slightly out of the ivotal axis of the frame, and a thermostatic element projecting into the pot and engaging the eccentric to cause a movement of the frame on its axis.

5. The combination with an electrically heated melting pot inounted for movement in a definite plane and a thermostatic device for controlling the temperature of the pot mounted thereon comprising a frame pivoted for movement in a plane perpendicular to the plane of movement of the pot,

an elongated switch member mounted thereon, an eccentric adjustably mounted in said frame and slightly out of its pivotal axis, and a thermostatic element projecting into the pot and engaging the eccentric to cause the frame to turn on its axis.

6. The combination with an electrically heated melting pot mounted for movement in a definite plane and a thermostatic device for controlling the temperature of the pot mounted thereon comprising a casing resiliently mounted on the pot for movement in the plane of movement of the pot, a frame pivoted in said casing for movement in a plane perpendicularto the plane of movement of the pot, an elongated switch member mounted on said frame, an eccentric adjustably mounted in said frame and slightly out of its pivotal axis and a thermostatic element projecting into the pot and engaging the eccentric to cause the frame to turn on its axis.

In witness whereof my hand this 17th day have hereunto set I of July, 1918.

ALBERT N. OTIS. 

